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Date: 07 Nov 2006 21:34:31
From: W. Watson
Subject: Projecting the Mercury Transit Onto Cardboard
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I'm going to try to use a pinhole in a cardboard sheet this afternoon, in
about 3 hours (PST), to see if there's any possibility that it might produce
an object as small as Mercury. I'll try to get the image into a darkened
box. I think there's a pretty good sized sunspot on the sun, so maybe
that'll give me some sort of clue as to what's up. Has anyone tried this
beore, and has suggestions? If it doesn't work, I'll get out my video camera
and use the scope to put it on a TV screen. Some kids will be viewing this,
and it would be good if the pinhole method works, so they can try it later
in the day. It looks like the two sunspots are shrinking rapidly. Well, they
are still there. Probably much bigger than Mercury.
Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet
--
"There is more to life than increasing its speed"
-- Mahatma Gandhi
Web Page: <home.earthlink.net/~mtnviews >
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Date: 07 Nov 2006 16:40:11
From:
Subject: Re: Projecting the Mercury Transit Onto Cardboard
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W. Watson wrote:
> W. Watson wrote:
>
> > I'm going to try to use a pinhole in a cardboard sheet this afternoon,
> > in about 3 hours (PST), to see if there's any possibility that it might
> > produce an object as small as Mercury. I'll try to get the image into a
> > darkened box. I think there's a pretty good sized sunspot on the sun, so
> > maybe that'll give me some sort of clue as to what's up. Has anyone
> > tried this beore, and has suggestions? If it doesn't work, I'll get out
> > my video camera and use the scope to put it on a TV screen. Some kids
> > will be viewing this, and it would be good if the pinhole method works,
> > so they can try it later in the day. It looks like the two sunspots are
> > shrinking rapidly. Well, they are still there. Probably much bigger than
> > Mercury.
> I see the Exploratorium has a better idea. A pinhole just doesn't have the
> resolution for such a tiny object. Use one lens of a 7 power binoc. All I
> need now is to find the tripod attachment to the binocs. :-)
>
> Maybe there are some other approaches like using a long tube with a pin hole
> over the end and a thin tissue over the other end.
>
You could try a reflecting pinhole. Cover a first-surface mirror with
some construction paper that has a 1/16th inch hole. Then reflect the
Sun's light into a building or other darkened area and onto a screen or
wall. You should get an image of the Sun almost 16 inches in diameter
at a projection distance of 150 feet. Mercury should be visible as a
small dot or smudge, about 2 mm across. You use a second-surface
mirror of you can keep the Sun's rays relatively close to
perpendicular, or if the glass is very thin. Keep the viewing area as
dark as possible.
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Date: 07 Nov 2006 23:25:19
From: W. Watson
Subject: Re: Projecting the Mercury Transit Onto Cardboard
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W. Watson wrote:
> I'm going to try to use a pinhole in a cardboard sheet this afternoon,
> in about 3 hours (PST), to see if there's any possibility that it might
> produce an object as small as Mercury. I'll try to get the image into a
> darkened box. I think there's a pretty good sized sunspot on the sun, so
> maybe that'll give me some sort of clue as to what's up. Has anyone
> tried this beore, and has suggestions? If it doesn't work, I'll get out
> my video camera and use the scope to put it on a TV screen. Some kids
> will be viewing this, and it would be good if the pinhole method works,
> so they can try it later in the day. It looks like the two sunspots are
> shrinking rapidly. Well, they are still there. Probably much bigger than
> Mercury.
I see the Exploratorium has a better idea. A pinhole just doesn't have the
resolution for such a tiny object. Use one lens of a 7 power binoc. All I
need now is to find the tripod attachment to the binocs. :-)
Maybe there are some other approaches like using a long tube with a pin hole
over the end and a thin tissue over the other end.
Wayne T. Watson (Watson Adventures, Prop., Nevada City, CA)
(121.015 Deg. W, 39.262 Deg. N) GMT-8 hr std. time)
Obz Site: 39° 15' 7" N, 121° 2' 32" W, 2700 feet
--
"There is more to life than increasing its speed"
-- Mahatma Gandhi
Web Page: <home.earthlink.net/~mtnviews >
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